In connection with such and related RF pulse transmitters, the art has heretofore made copious use of parallely connected half-cycle generators of the type using switching solid state SCR thyristor switching circuits as described, for example, in U.S. Pat. No. 3,711,725, "Apparatus and Method for Radio-Frequency Pulse Generation in tuned Radio-Frequency Loads"; U.S. Pat. No. 3,786,334, "Magnetic Pulse Compression Radio-Frequency Generator Apparatus"; and U.S. Pat. No. 3,889,263 "Radio Frequency Pulse Generation System and Method", of common assignee with the present invention and exemplarily applied to Loran-C type transmitters and the like.
In such and related half-cycle generation circuits, to minimize SCR losses, priming and sweep-out circuits are employed in series with the main power SCR thyristor to delay the anode current until the full SCR junction area is turned on--such delay preferably being attained by the use of square-loop saturable inductors as described, for example, in U.S. Pat. No. 4,230,955, "Method of and Apparatus for Eliminating Priming and Carrier Sweep-Out Losses in SCR Switching Circuits and The Like", and U.S. Pat. No. 4,674,022, "Improved SCR Priming and Sweep-Out Circuit Apparatus", also of common assignee. Such circuits also require the clamping of reverse voltages on the energy-supplying capacitors to prevent excess voltage across the capacitors, and such clamping circuits have heretofore been provided in successively operated half-cycle generators, by separate clamping power supplies--quite effective, but resulting in losses of substantial output power.
It is to the substantial elimination of such losses through novel substantially lossless capacitor clamping circuits and lossless series regulation of the circuit as well, that the present invention is primarily directed and, while further providing increased immunity from the effects of the false triggering of the SCR switches caused by direct lightning strikes on the antenna and/or by other load-shorting phenomena.